If we would like to implement ldap authentication as well as password authentication for some users at a same time (like authentication type as password, global in oracle), Is there any option with postgresql 12? I did tested password authentication and as well as ldap authentication users separately by touching pg_hba.conf file, it works separately but not at the same time for different users..
Yes, you can have different methods at the same time for different users. pg_hba has a user column for this purpose. It is entirely unclear what specifically you tried, and what about it didn't work. This is much too vague to be a valid bug report.